150 ESSA YS. 



era China, — belongs, therefore, to the eastern Asiatic tem- 

 perate region, of which northern China is a part, and Japan, 

 as we shall see, the portion most interesting to us. There is 

 only one more species of Torreya, and that is a companion of 

 the Redwoods in California. It is the tree locally known 

 under the name of the California Nutmeg. Here are three 

 or four near brethren, species of the same genus, known no- 

 where else than in these three habitats. 



Moreover, the Torreya of Florida is associated with a Yew ; 

 and the trees of this grove are the only Yew-trees of eastern 

 North America ; for the Yew of our northern woods is a de- 

 cumbent shrub. A Yew-tree, perhaps the same, is found with 

 Taxodium in the temperate parts of Mexico. The only other 

 Yews in America grow with the Redwoods and the other 

 Torreya in California, and extend northward into Oregon. 

 Yews are also associated with Torreya in Japan ; and they 

 extend westward through Mandchuria and the Himalayas to 

 western Europe, and even to the Azores Islands, where occurs 

 the common Yew of the Old World. 



So we have three groups of coniferous trees which agree in 

 this peculiar geographical distribution, with, however, a nota- 

 ble extension of ran^e in the case of the Yew : first, the Red- 

 woods, and their relatives, Taxodium and Glyptostrobus, which 

 differ so as to constitute a genus for each of the three regions ; 

 second, the Torreyas, more nearly akin, merely a different 

 species in each region ; third, the Yews, still more, closely re- 

 lated while more widely disseminated, of which it is yet un- 

 certain whether they constitute seven, five, three, or only one 

 species. Opinions differ, and can hardly be brought to any 

 decisive test. However it be determined, it may still be said 

 that the extreme differences among the Yews do not surpass 

 those of the recognized variations of the European Yew, the 

 cultivated races included. 



It appears to me that these several instances all raise the 

 very same question, only with different degrees of emphasis, 

 and, if to be explained at all, will have the same kind of ex- 

 planation. 



Continuing the comparison between the three regions with 



